Cooperative brake and driving device for a recording machine



May 20,1969 R. slsssm'uub COOPERATIVE BRAKE AND DRIVING DEVICE INVENTOR (f M M1,? Mailer! FOR A RECORDING MACHINE Filed lay 31, 1966 United States Patent i US. Cl. 242-5512 9 Claims ABSTRACT OF THE DISCLOSURE A driving device for a magnetophone with a rewindable recording carrier having two winding plates disposed spaced apart and a motor means including a frictional clutch for selective driving engagement with one of the recording plates. A setting means including an operating member is provided for pivoting the motor into driving engagement and includes an elastic means yielding connected between the motor and the operating member for pivoting and retaining the motor in driving engagement against one of the winding plates Brake means are pro vided engaging each of the winding plates respectively, which are adapted to have a stronger effect than that of the friction clutch, and the brake means and the setting means are operatively connected for releasing the brake, when the setting means is actuated.

The present invention relates to a driving device for a magnetophone with a rewindable recording carrier and a motor, which is connectable by means of a slip clutch to the prevailing winding spool plate which can be controlled by a controllable brake device.

In known devices of this type the joining force of the slip clutch is measured such, that during the start, the tensile strain created in the recording carrier, due to the mass inertia of the unwinding spool, does not surpass this predetermined measure. The brakes on [the windingand unwinding-spoolplate serve the purpose to destroy the moving energy contained in the recording carrier and the spool plates, respectively, upon stopping of the drive, in order that the moving energy cannot lead to a loop formation or non-tolerable pulling tensions in the recording carrier. This known device suffers by the basic drawback, that the finding of a predetermined position of a listening occurrence is thereby not possible, because the rewinding acceleration of the recording carrier is too great. If the slip coupling is set weakly correspondingly, the starting time is too long during a fast rewinding.

Furthermore, a driving device is known, which causes the joining of the winding spool such, that a belt engaging the spool plate is pressable increasingly towards the spool plate. Here, different accelerations could be obtained by corresponding control of the engaging pressure. It would bring about the drawback, however, that the actual driving element cannot be arranged as its optimum for the plain driving conditions, since it has to be effective simultaneously as a slip clutch. A corresponding arrangement with friction wheels would suffer of the same drawbacks. Furthermore, it is not still to be added that undesirably high engaging pressures would be necessary, instead of the conventional self-wedge effect.

Another device with an engageable and disengageable disk clutch is known. This clutch is, however, not arranged for selective accelerations.

It is one object of the present invention to provide a driving device for magnetophones with a windable recording carrier, wherein the drawbacks of the known structures are avoided.

3,445,075 Patented May 20, 1969 It is another object of the present invention to provide a driving device for magnetophones with a rewindable recording carrier, wherein the braking device is more effective than the slip clutch and can be increasingly detensioned by means of an operating element for obtaining the driving connection between the motor and the spool plates with an intermediate arrangement of a spring during the connecting path.

With such an arrangement, it is possible to start the recording carrier, on the one hand, from zero with the smallest acceleration values, on the other hand, however, also with a maximum acceleration force. No compromise in the driving means or additional devices are required, since the brakes are required anyway in most instances.

It is still another object of the present invention to provide a driving device for a magnetophone with a rewindable recording carrier, in which the operating element for the obtaining of the driving connection between the motor and the spool plates has a neutral position from which it is movable in one direction for coupling one of the spool plates and in opposite direction for coupling the other of the spool plates and has an elastic coupling directly yieldingly connected between the operating element and the motor, and comprising a brake for each spool plate which has a stronger effect on the spool plates than the friction clutch of the motor.

By means of this arrangement it is possible, to correct the recording carrier by means of an operating element exactly to the desired position.

With these and other objects in view which will become apparent from the following detailed description, the present invention will be clearly understood in connection with the accompanying drawing, in which:

FIGURE 1 is a top plan view of a sound tape device, shown schematically; and

FIG. 2 is a fragmentary elevation of the device disclosed in FIG. 1.

Referring now to the drawing, the device, designed in accordance with the present invention, comprises two winding plates 1 and 2 and a motor 3 is mounted between the winding plates 1 and 2 for a tipping movement about two axles 4. The motor 3 has a shaft 6 and a disk 7 is rigidly secured on the shaft 6. A friction disk 8, which is rotatably mounted on the shaft 6, is urged towards the disk 7 having an intermediate friction layer 10 by means of a pretensioned spring 9. A spiral spring 5 is secured to one of the axles 4, the free end of the spiral spring 5 being connected with an operating rod 11. By displacement of the operating rod 11 in its longitudinal direction, the motor 3 is selectively coupled directly with the winding plate 2 or by means of an intermediate wheel 12 with the winding plate 1, the motor 3 swinging about its axis 4 into the respective coupling positions.

The winding plates 1 and 2 are surrounded by band brakes 13 and 14, respectively, which is connected at its free end with one arm of double-armed, angular levers 15 and 16, respectively. The other arm of the doublearmed lever 15 and 16, respectively, is connected on the one hand, with springs 17 and 18, respectively, and, on the other hand, is controllable by a recording carrier 21 by means of pins 19 and 20, respectively. The doublearmed levers 15 and 16, respectively, is connected on the more pretensioned spring arms 22 and 23, respectively, which engages control cams 24 and 25, respectively, of a displaceable rod 26.

The sum of the spring forces 17, 22 and 18, 23, respectively, is of such measured value, that the spring forces exert, in the shown resting position of the device, a greater force upon the winding plates 1 and 2, than that of the friction moment between the disks 7 and 8 upon the motor shaft 6, when the friction disk 8 is coupled to one of the winding plates 1 or 2 by operation of a lever 27,

which is mounted for a Swinging movement in an immovable pin 27' and pivotally secured to the displaceable rod 26; that means that the recording carrier 21 is initially not yet moved. Its increasing pulling tension is limited by the friction coupling 6, 7 and 8. Upon further swinging of the lever 27, for instance, in the direction of the arrow V, the spring 22 slides down at first from its control cam 24 and its tension is released, the braking moment exerted by the band brake 13 is rendered smaller than the driving moment exerted by the drive shaft 6. The recording carrier 21 cannot move yet, since the spring 23, acting upon the winding plate 2, is still under tension. It is merely taut and releases the effect of the spring 17, which causes a complete release of the band brake 13. This band pull is insufiicient, however, in order to release the effect of the spring 23. Upon further swinging of the lever 27 in the direction of the arrow V, the spring 23 loosens increasingly its tension, by sliding on the inclined face 28 of the control cam 25. Slowly the point is reached, at which the driving moment exerted by the motor shaft 6 becomes greater than the brake moment exerted by the brake bands 13 and 14. The recording carrier 21 is set thus into motion at first with a very small acceleration force, in case the lever 27 is not moved immediately to a complete release of tension of the spring 23.

If the lever 27 is moved in the direction of the arrow R, so that the motor 3 is coupled with the winding plate 2, the same operations take place in opposite direction relative to the springs 17, 22 and 18, 23, respectively.

It is also possible, to make such arrangement, that upon coupling the winding plate 1 with the motor 3 at first the brake 14 of the Winding plate 2 is released and then only hesitatingly the brake 13 of the winding plate 1.

I claim:

1. A driving device for a magnetophone with a rewindable recording carrier, comprising two winding plates disposed spaced apart from each other and having parallel axes of rotation,

a motor having a shaft and being swingably mounted for selective movement to operatively drive either one of said winding plates,

a first disc rotatably mounted on said motor shaft,

a friction clutch including a second disc cooperatively disposed between said first disc and said motor shaft,

an intermediate wheel between said first disc and one of said winding plates,

said first disc being selectively movable with said motor into operative driving engagement with either said intermediate wheel or the other of said winding plates to correspondingly drive the selected winding plate,

means for setting selectively said motor to drive either one of said winding plates through said first disc,

said setting means including an operating member and an intermediate elastic means yieldingly connected b tween said operating member and said motor for swinging and holding said motor in position to drive one of said winding plates upon selective actuation of said operating member from a neutral non-driving position to a selected winding plate driving position,

a brake means engaging each of said winding plates,

respectively, and

said brake means adapted to have a stronger effect than that of said friction clutch.

2. The driving device, as set forth in claim 1, further comprising connecting means operatively connecting said setting means and said brake means for cooperative actuation of said brake means and said setting means together.

3. The driving device, as set forth in claim 2, wherein said connecting means including means for causing said brake means to gradually release slowly upon actuation of said setting means when said motor is selectively swung into position to drive one of said winding plates and for rapid release of said brake means,

respectively, upon slow and rapid actuation, respectively, of said setting means.

4. The driving device, as set forth in claim 1, wherein said brake means includes a band brake.

5. The driving device, as set forth in claim 1, wherein said brake means includes,

a spring-biased double armed lever means disposed pivotally adjacent each of said winding plates,

a band brake at least partially encircling each of said winding plates, respectively, and having one end thereof immovably secured,

one arm of said lever means connected to the other end of the corresponding band brake,

spring biasing means for each of said levers for tending to pivot said levers in a direction to tighten said band brakes,

both of said winding plates adapted to have wound thereabout a recording carrier slidingly disposed against both of said lever means, tending to pivot the latter in a direction so as to loosen said band brakes when said recording carrier is taut, and

said spring biasing means of sufiicient strength for braking the corresponding of said winding plates via said hand brake when said recording carrier is not taut against a driving engagement force of said first disc.

6. The driving device, as set forth in claim 5, wherein said brake means further includes,

a pre-tension means on each of said levers, respectively,

a displaceable rod operatively connected with said operating member of said setting means and including two cam means each positioned on said displaceable rod in sliding abutting relationship relative to said pre-tension means of said lever means, respectively,

each of said cam means adapted to cooperate abuttingly with said corresponding pre-tension means to prevent said recording carrier from pivoting the corresponding lever means to loosen the corresponding band brake, and

said displaceable rod adapted to be displaced upon movement of said operating member so as to move said cam means out of abutting cooperation with at least one of said corresponding pre-tension means.

7. The driving device, as set forth in claim 6, wherein said pre-tension means is a pre-tension spring secured to said lever means.

8. The driving device, as set forth in claim 7, wherein said cam means each includes a peak, a sharp slope on one side thereof, and on the other side thereof a gradual slope, respectively,

both cam means being disposed relative to one another in mirror image symmetry and spaced from one another in a neutral position abutting thereof with both of said peaks both of said pre-tensioning springs, simultaneously, and

said brake means is simultaneously adapted as a manually operating starting control and setting correction means.

9. A driving device for a magnetophone with a rewindable recording carrier, comprising two winding plates disposed spaced apart from each other and having parallel axes of rotation,

a motor having a shaft and being swingably mounted for selective movement to operatively drive either one of said winding plates,

a first disc rotatably mounted on said motor shaft,

a friction clutch including a second disc cooperatively disposed between said first disc and said motor shaft,

an intermediate wheel disposed between said first disc and one of said winding plates,

said first disc being selectively movable with said motor into operative driving engagement with either said intermediate wheel or the other of said winding plates to correspondingly drive the selected winding plate,

means for setting selectively said motor to drive 5 6 either one of said winding plates through said first References Cited disc, UNITED STATES PATENTS said setting means including an operating member and 1 789 607 1/1931 Steurer an elastic means yieldingly connected between said 2526783 10/1950 Toogoo'd Warming member and Said mow! Swinging and 5 31076161 8 2/1963 Van Hook 24275.4 2 retaining said motor in position to drive one of said 3,091,410 5 /1963 Widener 242 55.12 winding plates upon selective actuation of said 3,093,335 6/ 1963 Lane 24255.12 ting means swinging said motor by said operating 3,133,710 5/ 1964 Herterich 242-55.12

member froina neutral non-drrvmg position 1nto po- 10 GEORGE E M AUTZ, Primal}, Examinersition for dl'lVlIlg one of said W1nd1ng plates and into position driving the other of said winding plates US. Cl. X.R. through said intermediate wheel, respectively. 242 75.42 

